[I received a copy of this book through NetGalley, in exchange for an honest review.]

The kind of format I like (and I probably missed on a lot more, considering I had a digital copy, not a paper one), mixing extracts from diaries, interviews and camera clips, as well as a non-chronological narrative and an unreliable narrator.

The story mostly revolves around Carly and Kaitlyn, twin sisters of sorts, or perhaps not? They're two minds in one body, and who can tell whether one is crazy and the other just a mere symptom, or whether they're actually two souls who just happen to coexist in an unusual way—Carly during the day, and Kaitlyn at night? After their parents' death, the "sisters" are sent to Elmbridge, a boarding school in Somerset, but their stay there is chaotic, as they're regularly sent back to Claydon, a psychiatric facility for teens. Under the guidance of Dr. Lansing, Carly has to accept that Kaitlyn is only an alter, meant to hold the painful memory of the night when her family was torn asunder. And yet... Doesn't Kaitlyn exist in her own way, too? Is she a construct, or a real person? Doesn't her diary reflect how real she is, just as real as Carly?

"The Dead House" explores this idea, mainly from Kaitlyn's point of view, but also through Naida's camera footage and through the group of friends gathered around her: Naida, Carly's best friend during daytime; Scott, Naida's boyfriend; and Brett and Ari. Naida's peculiar in her own way, in that she comes from a family of priests, brought up within the faith of "Mala", an Scottish mix of traditional witchcraft and voodoo (it doesn't actually exist, and was created specifically for this story). And she may be the only one to accept that Kaitlyn/Carly is something special, something unique.

However, there's something rotten in the Dead House: the sisters grow estranged, pills may do more harm than good, the doctor may not be so competent as she thinks she is, and Kaitlyn's losing herself more and more in the maze of her own mind. Fascinating elements here, that I really liked reading about. Creept imagery, too, even though I've read more gory and morbid.

I'm torn when it comes to other aspects of this book, though. First, the Mala part, which sometimes felt strange and... "not Scottish"? There was something unsettling about the names, whether the spirits' or even the people's ("Naida" and "Haji" definitely don't sound Scottish, and their French family-name hints more at New Orleans/voodoo surroundings than British ones). It would also have been interesting to see a real set of beliefs used here, rather than an imaginary one.

Then the romance, which I didn't particularly care about, as the story could likely have stood on its own just as well with pure friendship and similar relationships. (But I'm very nitpicky when it comes to romance, so don't mind me here.) The love interests looked really flat compared to Kaitlyn. In fact, most characters seemed flat, including Carly. Perhaps more insights into her own diary, into the post-its the sisters left for each other, would have helped to get to know here better. As it was, I didn't really care about her either.

I was also confused about the actual time when the story was set: the diary and footage were recovered more than 20 years later, yet there's no real sense of "the future". It could've been 2015, and it would've been just the same. As for the ending, it felt incomplete, and I couldn't decide whether the supernatural element was a good thing, or if I would've enjoyed the novel more if it had been purely a matter of psychological disorders.

As it was, I did enjoy "The Dead House", and I give it 3.5 stars out of 5. On the other hand, I can't help but think that something was missing—perhaps several things, even.